Probably it's because it's Casey and we all saw how he started out. People are trying to encourage his experimentation? I dunno. Fuuma pulls off lots of things that mere mortals cannot. Part of this is the Fuuma factor. The other part is that many times people try to do it with poor/cheap approximations rather than the real deal (when it comes to specific pieces).
It comes down to very little:
-I tend to wear shawl collars or unusual fabrics, these characteristics lend themselves much better to the white tee+tux+jeans look.
-Right brands/cuts: more louche than formal.
-I have the kind of face/haircut/facial hair you'd expect on a nightlife douchebag wearing a tux jacket casually